


Swallow Yourself Whole.

by Absolute_Trash37



Category: Supergirl (TV 2015)
Genre: Angst with a Happy Ending, F/F, Happy ending is... debatable., Kara Danver Doesn't Know that Lena Luthor Knows, Kara Danvers Needs a Hug, Lena Luthor Knows Kara Danvers Is Supergirl, Lena Luthor Needs a Hug, Post-Traumatic Stress Disorder - PTSD, Red Kryptonite Kara Danvers, Trust Issues, i know big surprise with me, no one dies
Language: English
Status: In-Progress
Published: 2018-11-03
Updated: 2018-12-23
Packaged: 2019-08-17 07:15:32
Rating: Not Rated
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 3
Words: 4,379
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/16511720
Author URL: https://archiveofourown.org/users/Absolute_Trash37/pseuds/Absolute_Trash37
Summary: Agent Liberty and Supergirl face off. The only problem is that he has Red Kryptonite. Shouldn't be a problem with the new anti-kryptonite suit Lena made for her right? Right. But when the mask is cracked and Kara is both faced with Agent Liberty's Red Kryptonite and the normal Kryptonite that's currently in the atmosphere, Kara goes after the people who have harmed aliens.And in her haze of pure fury, she goes after the woman who learned how to make Kryptonite, the woman whose brother was the most notorious alien-hater of all time: Lena Luthor.





	1. Code Red

After Kryptonite was released into the atmosphere and Lena gave Supergirl the new suit, the DEO hadn't heard much from the Luthor, who was working on a more conventional way to prevent the Kryptonite from affecting Kara. They only saw or heard from her when she chose to emerge from whatever lab she spent her days in now. Their best bet was to call Eve or Jess and have them notify Lena that she was needed or that Alex wanted her to “turn her goddamn phone off mute, she could be dead for all we know”.

Kara had been struggling too, because she couldn't find Lena as Supergirl (again, Lena was only heard from when she wanted to be), and she couldn't visit as Kara because of the fact that she couldn't leave the suit. Alex had some sympathy for the Kryptonian. Yet, Alex was primarily concerned by the fact that she was 99.9999999% positive that while working on Supergirl's newer-new suit, Lena was also looking for Mercy and Agent Liberty. An endeavour that, with Lena's track record, would get her killed.

Thankfully, it was the DEO that located Liberty first and pinged his location. 

“Kara, he's at-”

“The alien bar...” Kara had scarcely reacted as quickly as she did, and that was when Alex or Lena was in danger. Alex's order had to be given over the comm, because Kara was gone the second she said the word “bar”.

“Kara, you have to be careful, it might be a trap. We haven't been able to ping his location until he already wreaked havoc before, there has to be a reason we got the location so early this time.” Alex warned as Brainy sat in the chair that used to belong to Winn. 

“I know Alex, I know. But I'm not letting him hurt the aliens at the bar, I won't let him ruin their one safe space.” Kara got to the bar fairly quickly and instantly spotted Agent Liberty. 

“EVERYONE OUT!” She ordered, and Agent Liberty turned to face her as the cowering aliens scattered.

“Leave now, you don't have to do this.” Supergirl's voice was stern, and still very clearly hers, even through the suit. Agent Liberty had no reaction to her words, at the same time the mask hid all sense of emotion. “They haven't harmed you, or anyone, they're innocent, they're kind. They have lives, just like you do.” Kara reasoned further. 

“They're cockroaches, even if they haven't physically harmed anyone, they've caused pain, through taking jobs, through being here. They have no right. You have no right.” Liberty pulled a seemingly harmless pistol from his waist, and a stick of red kryptonite fell from his sleeve into his other hand. 

“We both know that can't hurt me.” Supergirl tried to prevent a scene. Liberty took a series of strides to get closer to Supergirl and ducked when she threw a punch. He placed the pistol against the glass of her helmet and fired, causing spider web cracks to appear from where the bullet lodged itself. 

“All I needed was a crack.” Agent Liberty held the red kryptonite up by her cracked helmet before he ran off, having exposed her to both the kryptonite-laced atmosphere and the red kryptonite. 

Kara quickly started to claw at her mask as the unfiltered air seeped into the suit. Soon, Kara was on her knees, wheezing in pain. Her vision started to cloud, things blurring and swaying while she knelt in place. As her breathing started to labour, Kara slowly fell to her elbows, before she rolled onto her back and the world around her faded to black. 

“Supergirl!” Alex rushed into the bar along with some other DEO agents. They all hurried to get Supergirl out of there. As Alex and the agents all rushed Supergirl back to the DEO where Brainy was preparing the replacement mask, Vasquez got to the bar so she could fill out a report. When she arrived she found the red kryptonite. 

“Oh no.” Vasquez activated her comm, cautious since Alex would likely start yelling at her after she delivered the news.

“Uhm... Director Danvers, we have a situation.”

“What situation!?” Alex yelled, occupied with her sister. 

“Just, please don't shoot the messenger.” Vasquez bagged the kryptonite and took in a deep breath. “I think Kara has come in contact with red kryptonite, I think that's why Liberty broke her mask.” 

“She's WHAT!?” Alex yelled out in horror. Vasquez listened as Alex gave orders to the agents that rode with her. 

“Vasquez, I don't recommend coming back to the DEO.” Alex turned her comm off. The DEO Director knew that with the Kryptonite in the atmosphere, they couldn't take off Kara's suit, and at the same time, they couldn't restrain her while the suit was on, meaning Kara was a danger to herself and others.

The arrival to the DEO was fast and hectic. Alex helped another agent pull Kara onto a gurney.

“Brainy, she's under the influence of red kryptonite, we need to restrain her, what do we do?” 

“The only thing on this planet that can weaken her is Kryptonite, but the suit prevents Kryptonite from affecting her... yet she will die without the suit. We are in quite the predicament...” Brainy continued to mumble to himself as he replaced the mask. “Please do not wake up a homicidal sociopath, Kara Zor-El.” 

“How long will it take for the Red Kryptonite to leave her system?” Brainy asked the elder Danvers sibling.

“I don't know, it was days last time, it didn't wear off until she and J'onn fought, according to Clark, it wears off naturally within a weak, or we need to wait for her to get a burst of adrenaline or for something to snap her back to her senses.” Brainy inserted the mask firmly as Alex spoke.

“Well, let us hope she faces something to bring her back to her senses.” Brainy looked at Alex solemnly. 

It had been a few hours since the initial incident, and Alex was sitting next to Kara's cot, desperately and fearfully waiting. 

“Kara... I know you're going to be out of it for a while, and I know you won't have any control over it.” Alex looked over to Kara. “Look, I love you, Kar. And I'm sorry you're about to go through this again... and I forgive you. You're good, Kara, so so good, and it's not your fault, it's not.” Alex placed a hand on Kara's, brushing her thumb over the fabric. 

“Alex...” The DEO Director's head snapped up.

“Kara, hey...” The woman looked through the clear mask and sighed sadly at the glow of red in her veins. “What do you remember?” Kara slowly began to sit up

“Liberty...he attacked the bar... he was going to kill the aliens there... they're innocent. He was going to kill innocents...” Kara growled, anger simmering in her voice, her hands were curled firmly around the edge of the cot. 

“Kara, take a deep breath, calm down.” Alex tried to persuade Kara, well aware of what this could lead to. 

“No, Alex! Ever since the President's identity was revealed, people have been horrible to aliens! It's not right, they haven't done anything! They don't deserve this!” Kara jumped off the cot and started to pace furiously. “I'm sick of it! I'm sick of people harming thousands, killing aliens out of fear and hate, when they have no reason to hate them! I'm tired of people following the ideals of organizations like CADMUS! I'm finished letting people like Lex Luthor and Agent Liberty roam free... they deserve to die. Mercy deserves to die, Liberty deserves to die... every Luthor deserves to die.”

“Kara, you don't mean that-” Alex tried to argue.

“Don't I!? Lex should be dead, but Clark let him go, Clark spared him. Lionel was a horrible man, and Lillian is even worse. It's only a matter of time before Lena is swayed to their cause.”

“Kara, Lena would never try-” 

“SHE MADE KRYPTONITE! What makes you think she wouldn't use it on me?” Alex wanted to explain how, even if Lena wanted to, she was too in love with Kara to ever hurt her.

“She should be put down before she gets the chance.” Kara glared at Alex before she turned on the opaque feature on her mask and the glass faded to black. 

“What are you going to do?” Alex stood defensively, although there was nothing she could do to stop Kara.

“What I should have done the second I met her.” Kara flew out of the room in a blur, on her way to L-Corp in a blind fury.

Alex immediately pulled out her phone, just to get Lena's voicemail, the Director called Eve.

“Hello, Director Danvers, what can I do for you?” 

“Look, Eve, Kara is under the influence of Red Kryptonite, she's not herself, and she will stop anyone in her way, so you have to warn Lena that she will get to the building any second, and then you need to get out. Warn Lena, then get everyone out, NOW!”

“Jess heard you and is clearing the building, and I'll try to warn Lena.” 

“What do you mean try?”

“She's turned off her phone and her intercom, all I can do is get up to the top floor, but I think we might already be too late...” 

“Why do you say that?” 

“Because I'm on the seventh floor, looking out a window, and I can see a little blue dot getting closer and closer to the building...” 

“Fine, just get out of there and lock down the building, I'm on my way. Just... hope that Kara doesn't go through with it.” Alex ordered as she quickly got out of the DEO.

“With what?” 

“Killing Lena.” Alex answered and hung up.

**Notes for the Chapter:**

> I know this bit was dull, but the next two chapters are extremely intense.


	2. Some Mistakes Can Never Be Undone

**Summary for the Chapter:**

> Kara finds Lena. Shit goes down.

Lena was hard at work, making designs for Kara's new suit, hunting down Mercy and Agent Liberty, responding to emails, signing off on projects in the lab and arranging meetings. 

She took a deep breath when she heard two feet plant themselves behind her. 

“Still not an entrance, Supergirl.” Lena turned to face the hero and immediately knew something was wrong, even through the black visor. “What's wrong?” Lena stood from her chair and moved closer to the Kryptonian, but Kara moved away.

“What are you planning?” Lena furrowed her brow in confusion.

“Do you mean for your suit? I think I have a decent idea, but bringing the fortified design to life will be tricky.” 

“I mean when are you planning to betray me? Deactivate the suit like you deactivated the alien masking device.” 

“Wait-what? I would never, I don't even think it's possible, and Mercy hacked L-Corp to render the masking device useless, I had no part in causing it.”

“How can anyone be sure of that! Luthors are liars at heart, for all I know you aren't even capable of telling the truth.” Lena swallowed her heart and forced away tears. 

“I'd like you to leave, I think you know the way out.” Lena made the mistake of turning around, and Supergirl spun her and wrapped a hand around Lena's throat. The Kryptonian used her super strength to bring Lena to a pin on her window. The young Luthor clawed at Kara's hand desperately, trying to choke something out. 

“I should have killed you the second I found out you knew how to make Kryptonite, I should have killed you before you had the chance,” Kara spoke through the black of her mask and Lena moved her hands to firmly grasp at the hero's wrist.

“If you're going to kill me, at least let me see your face,” Lena's strain caused a tear or two to slip past her. Kara listened and turned off the opaque feature, leading the glass to reveal Kara's face and the red glow of her veins, Lena blinked slowly, accepting her fate. 

“I'm sorry,” Lena muttered lowly as Supergirl's grip slowly tightened, soon Lena wouldn't be able to get out a single word. 

“Yes, you're sorry, now that your actions are getting consequences.” Kara growled out, the red under her skin was glowing brightly. For a split second, Lena wondered how Kara was affected by red kryptonite while in the suit. 

“Look... this isn't you... but if this is something you need to do, I understand, and I forgive you, Kara. I forgive you.” Lena had to breathe out the words, knowing in seconds her airway would completely be cut off.

“Just because I can finally see the light, just because I'm finally giving you what you deserve, 'I'm not myself'!” The woman took a second to think about Lena's words. “Kara... you called me Kara... you knew! You knew! How long was it going to take you to use that against me too!?”

“I would never... I was waiting for you to trust me enough to tell me...” Lena let out a terrified intake of air and Kara squeezed harder.

“I would never trust a Luthor.” Kara's eyes fixated on Lena's, watching as the light started to fade from her eyes. Lena acted quick and shifted slightly so she could give one last reprise. 

“I don't blame you... there are days I don't trust me either. But I would never hurt you, never... I-I-” Kara's hand wrapped tightly, and Lena had no way of buying herself more time. The CEO accepted her fate, but her legs started kicking and spasming instinctively as oxygen was cut off from her brain. 

“KARA!” It was Alex, horrified by the scene in front of her. Kara had Lena pinned against the window, feet off the ground, the glass cracking from how much Kara was pushing Lena into the window. 

“You don't want to do this, Supergirl,” Alex warned, cautiously approaching the scene in front of her. 

“It's all I want, for alien-hating scum to be wiped from the universe.” 

“Kara, look at me.” Alex scolded herself for revealing Kara's identity to two people today, so much paperwork. The blonde obeyed and looked at the DEO Director. 

“Lena is not like her family, you taught me that, you taught everyone that. She made sure Lillian was imprisoned, made sure that Lillian couldn't harm aliens ever again, she made Kryptonite because before Supergirl, all she knew from Kryptonians was hate: Zod, Non, Astra, she probably wanted to protect herself in case Superman ever tried to hurt her. She would never use it against you.” 

“We don't know that!” Kara snapped her attention at the quickly fading Luthor, not noticing the small slip in her grip.

“She's had every opportunity, and she hasn't, and she won't. And you know this too, you love her and she loves you, in a way that neither of you realize. And Kara, you will never forgive yourself if you do this, and no one else will either. Because you made us give her a chance, and now she's family, because you were right, she's smart, and brave, and kind, and generous, and so, so, so good.” Alex took a moment, her voice wavering at the fear that she wouldn't be able to save Lena. “Let her go.”

“I WAS BLIND!” Kara yelled, fury and distress in her voice, and Alex knew she was close to breaking through. 

“No, you see Lena more clearly than anyone else in the world. Look at her, look at your best friend, look at what you're doing, Kara, please.” Lena weakly pulled her watery eyes open and looked at Kara, barely able to speak, but Kara's hand loosened enough to manage.

“It's okay... I failed you, and it's okay... I-I'm sorry, Kara.” Kara's hand tightened with a scream as the CEO finished her sentence and the last syllable came out as a squeak from Lena's mouth. 

“Kara, NO!” Alex yelled, not able to see the fade of the red glow, or Kara's angry tears, or the look of horror on her face as she realized what she was doing and she watched Lena's hands fall limply at her sides. 

“No... no... Lena... oh Rao, no, no, no, Lena!” Kara's hand instantly lost all strength and Lena limply fell to the floor.

**Notes for the Chapter:**

> Sorry?


	3. Trauma

**Summary for the Chapter:**

> Big Oof.

Lena fell limply to the floor, arms moving to take impact at the last second and she landed with a coughing fit. Had it taken a second longer, the CEO wouldn't be coughing, her body would be lying still without any chance of saving her. 

“What have I done..?” Kara backed away from the injured CEO, looking between Lena and Alex in horror. “I-I'm sorry...” Kara flew away without another word. Alex was torn, wanting to go after her sister, but knowing the Luthor needed her too. After coming to terms with the fact that finding Kara wouldn't be likely, Alex rushed to Lena's side. She knelt down and brushed her hand up and down Lena's back as her other arm held Lena off the ground. Alex noticed that Lena tried to pull away in fear, and Alex loosened her grip, still supporting Lena but allowing her space at the same time. 

“It's okay, you're okay,” Alex spoke softly, comfortingly. “You're safe.” 

“Why-” Lena's voice was coarse and speaking clearly brought her pain, but Alex knew that if she tried to stop the woman, it would cause an unnecessary argument. “Why did she let me go?” 

“She fought it, she knew she was hurting you and it terrified her... it was enough to snap her out of it, thankfully.”

“What was that... I-I thought for a second that she had... she had become like Reign... that she lost her soul.” Lena wheezed weakly, still grappling with what had just happened. The woman she knew and loved more than anything, the woman who saved her in so many ways, had just pinned Lena to a wall and tried to kill her. It was enough to cause denial, confusion, despair. 

“No. Agent Liberty broke the glass of her visor and exposed her to Red Kryptonite, and it was already in her system by the time we could repair the mask. If we didn't fix the suit, she would have died... but we couldn't contain her either due to the fact that the suit makes her immune.”

“I'm going to kill him.” Lena's voice was rough, but firm. “He doesn't get to hurt her like that... he... he...” Lena's eyes wandered aimlessly as her voice faded, exhaustion trying to take over. 

“Lena, come here.” Alex positioned herself against Lena's desk and pulled the CEO into her lap. Alex's arms wrapped around Lena tightly and comfortingly. Lena's head lolled weakly in the crook of Alex's neck. Briefly, Alex let go to activate her comm.

“Vasquez... Kara is no longer a threat, and I know I gave you the day, but I need you to go and make sure that everyone at the DEO is back at work. Send a couple agents to L-Corp and prepare to examine Lena, she's been injured.”

“Yes, Director Danvers.” Agent Vasquez's voice came over the comm eagerly. “I hope Ms. Luthor is alright.”

“Me too,” Alex replied before turning her attention to the weak brunette, whose breathing was raspy and slow. 

“At-at least Kara didn't hurt anyone... it could have been worse, like last time.” Lena pitched out tiredly, the strain showing. 

“Do be ridiculous, she loves you, Lena, she is so scared of losing you, this is probably one of the worst things she can imagine doing,” Alex explained.

“But Agent Liberty wants people to fear aliens... they'll cheer if they discover that she's harmed a Luthor.” 

Alex was about to retort when the office doors burst open. Jess and Eve stood there, looking exhausted and terrified as Alex held her favourite gun in their direction. 

“We-we saw Supergirl fly away and we got up here as fast as we could, but the elevator was locked down, we had to take the stairs.” Jess gave their explanation and Alex dropped her gun tiredly, emotionally exhausted. “Are-are you alright Miss Luthor?”

“I'm fine, Jess, thank you both.” Eve's eyes were still wide as she watched Lena rest weakly in Alex's lap.

“She did this to you... and I thought finding out that Kara Danvers was Supergirl would be the most insane thing to happen to me today.” Now it was Jess who had wide eyes, shocked. 

“Oh God, all the paperwork...” Alex whined before she threw her head down into Lena's shoulder, pained by the thought of it. 

 

* ** *

 

Kara sat on top of a particularly high mountain, finally able to stop moving, finally able to sit still and think.

Well, in all honesty, the first thing she did when she landed was scream, and she screamed until her throat was raw and she was barely preventing herself from using her heat vision.

So, yes, she had screamed, she was distraught, the guilt hurt her worse than the kryptonite had. Now she sat, rocking back and forth, shaking, mumbling to herself. 

“Lena...” Kara tried to piece together what happened, the full picture was quite faded, and Kara didn't like anything she remembered. “No, I didn't...” Kara saw herself pin Lena to the wall, choking the life out of her. “I wouldn't.” Kara spoke out. “I wouldn't... I wouldn't... I wouldn't.” Kara saw the scene flash through her mind again, on repeat. Her, attacking Lena, Alex's voice a million miles away and under water, the fear, the anger. Kara continued to rock back and forth as she remembered. 

She wouldn't... but she did. 

She hurt one of the people she cared most about, all because she had to dive into action, because she couldn't sit still and listen. 

“It wasn't you, it wasn't you, it wasn't you...” Kara continued to mumble to herself, shaking, at this moment she was as human as she could be, vulnerable, alone, desperate, horrified. She could tell herself that she wasn't to blame all she wanted, but it wouldn't change the fact that she had killed Lena, the woman she cared about, the woman she loved. She killed Lena and she was to blame, not Agent Liberty, not the Red Kryptonite, it was all her. She didn't know if she could face National City again, or Alex, or anyone she cared about, not after this. 

“Monster, monster, monster...” Kara's mumbling became aggravated and she desperately wished she could punish herself, or turn back time and take it back, take it all back. Part of her wished she had never met Lena, because she wouldn't have been able to hurt her had they never met, and if she still did, it wouldn't hurt this much. 

Kara sat, still rocking back and forth; weak, ashamed, angry, resentful, heartbroken and guilt-ridden.

She didn't want to believe she had done what she did. She _didn't_ believe it, but she knew.

She knew what she did, and that knowledge would haunt her for the rest of eternity. 

 

***

 

Lena was at National City Hospital, in recovery, Alex had tried to call Kara, had tried to find her, Alex had every Agent looking for the blonde, but she didn't dare leave the hospital, not with Lena in her current state.

Lena was relatively okay, thankfully. She had a concussion but that wasn't visible to the naked eye, it was her neck that took the most damage and held the most concern. It resembled a painters palette, dark blues and purples bruises speckled with yellow and pooled with red, an imprint that would stay as a constant reminder these next few weeks until they faded and some days it would feel like they'd never wash away. One doctor made the mistake of using his hands to try to check the bruising causing Lena to panic enough that she rolled out of the hospital bed and scampered to the edge of the room on her hands and knees in horror. Alex yelled at him for being so careless, that bruises like that don't just leave physical trauma, but mental as well. To say the least, Alex assured Lena got another doctor, one that was more careful. 

Most people came in to check on Lena, James came and went, more concerned with finding Kara, Brainy came and checked up on her and hoped she was having dreams filled with joy and content. Nia, Nia Nal came and visited, horrified to see one of her idols in her current condition, she stayed briefly before she left to go make a batch of cookies for when Lena felt better.

Alex watched Lena as she slept, making sure she kept breathing. Although the wheeze that accompanied the rise and fall of her chest was sad assurance enough. 

Alex had zoned out, thinking of the events that had conspired that day. 

“You can go, you know.” Lena rasped out, her voice raw and scratchy. Alex's head snapped up and she gave a sad smile to see the Luthor awake. 

“No way in Hell, little Luthor.” Alex teased kindly. 

“Y-you should be with Kara, she needs you right now, more than I do.” Lena insisted weakly.

“Everyone's looking for her, but honestly I don't think she wants to be found right now.”

“Not everyone... not you... not me” Lena's voice broke Alex's heart, weak, tired, rough. It was as if every word she said would be her last.

“You're not going anywhere in this condition.” 

“I have two companies to run,” Lena argued. 

“It'll be fine. Just, please, focus on getting better, no one will be able to rest until you're okay. Nia nearly fainted when I called her asking if she'd seen Kara, I played it off as though she'd want to know what happened.” Alex groaned. “Speaking of, after you're discharged you need to sign the confidentiality forms, Jess and Eve already did.”

“You must be behind on paperwork,” Lena empathized. “Go ahead I'll... I'll be okay...” Just the act of speaking alone caused Lena's eyes to water.

“No... it can wit, it all can wait what's important right now is you getting better, that's all I care about.

“Thank you...” Lena spoke quietly, not worrying about imposing or being a pain anymore.

She was too tired to care anymore.

**Notes for the Chapter:**

> I'm :) a :) horrible :) person :) who :) can't :) let :) herself :) or :) anyone ::)) else :) be:) happy :):):)


End file.
